Gastropoda Cuvier, 1795 see Class Gastropoda Cuvier, 1795
   Nudipleura Wägele & Willan, 2000
     Nudibranchia Cuvier, 1814 see Order Nudibranchia Cuvier, 1814
       Dexiarchia Schrödl, Wägele & Willan, 2001
         Cladobranchia Willan & Morton, 1984
           Dendronotoidea Sars, 1878 see Superfamily Tritonioidea Lamarck, 1809
             Family Hancockiidae MacFarland, 1923
               1 Genus Hancockia Gosse, 1877